A number of techniques are known for detecting areas of interest in an image, such as a face or other identified object of interest. Face detection is an area of particular interest, as face recognition has importance not only for image processing, but also for identification and security purposes, and for human-computer interface purposes. A human-computer interface not only identifies the location of a face, if a face is present, it may also identify the particular face, and may understand facial expressions and gestures.
Many studies on automatic face detection have been reported recently. References for example include “Face Detection and Rotations Estimation using Color Information,” the 5th IEEE International Workshop on Robot and Human Communication, 1996, pp 341-346, and “Face Detection from Color Images Using a Fuzzy Pattern Matching Method,” IEEE Transaction on Pattern Analysis and Machine Intelligence, vol. 21, no. 6, June 1999.
All the conventional methods of detecting human faces have their own advantages as well as shortcomings depending upon different algorithms used for processing images. Some methods are accurate but are complex and time-consuming.